Active Prominence

. When seen at the edge of the Sun, a filament takes the name prominence. This bright loop prominence outlines magnetic fields above sunspots; the loop is big enough to swallow the Earth. The photograph was taken in the green line of ionized iron, designated Fe XIV. [Courtesy of the National Solar Observatory (NSO), the National Optical Astronomy Observatories (NOAO), and the National Science Foundations (NSF).]